US regains top spot for fastest supercomputer

Agence France-Presse, June 19, 2012

An IBM supercomputer developed for US government nuclear simulations and to study climate change and the human genome has been recognised as the world's fastest.

The announcement Monday at the 2012 International Supercomputing Conference in Hamburg, Germany recognized Sequoia, an IBM BlueGene/Q system installed at the Department of Energy's Lawrence Livermore National Laboratory.

The machine delivered an impressive 16.32 petaflops -- a petaflop equating to a thousand trillion operations -- per second.

Sequoia is primarily for simulations used to ensure the safety and reliability of US nuclear weapons. It also is used for research into astronomy, energy, human genome science and climate change.

Sequoia dethrones Fujitsu's 'K Computer' installed at the RIKEN Advanced Institute for Computational Science (AICS) in Kobe, Japan, which dropped to the number two spot at 10.51 petaflops per second.

A new Mira supercomputer which is also part of the IBM BlueGene/Q series at Argonne National Laboratory in Illinois, was third fastest.

The most powerful system in Europe and number four on the List is SuperMUC, an IBM iDataplex system installed at Leibniz Rechenzentrum in Germany.

China, which briefly took the top spot in November 2010, has two systems in the top 10.

The announcement came from the TOP500 list compiled by the University of Mannheim, Germany; the Lawrence Berkeley National Laboratory and the University of Tennessee.

Artificial Disc Replacement

While hip and knee joint replacement surgery or arthroplasty has grown increasingly common since its advent in the early 1960s with a high degree of patient satisfaction, spine arthroplasty (or artificial disc replacement) has not been a viable option in the United States until recently.

The challenge has been to develop a suitable replacement for the intervertebral discs. The replacement must not only be safe to implant, reliable and long lasting, it also must have the ability to mimic the complex range of movement required of a disc. Efforts to find a solution to these challenges have been ongoing for more than 40 years.

Several artificial disc replacements for both the neck (cervical) and back (lumbar) spine are currently being offered to appropriate candidates at select U.S. centers.

An Alternative to Traditional Spinal Fusion

Age, genetics and everyday wear-and-tear of routine activities eventually can contribute to damage and degeneration of the discs that cushion the bones of the spine (the vertebrae). To treat degenerative disc disease, doctors usually begin with conservative (nonsurgical) medical treatment. When conservative therapy fails, other approaches, possibly including surgery, may be recommended. Currently, the gold standard for surgical treatment of problematic degenerative disc disease is spinal fusion. This procedure attempts to permanently lock two or more spinal vertebrae together so they cannot move except as a single unit. This may alleviate pain in a motion segment.

Spinal fusion, however, has well known potential disadvantages, including:

Loss of motion and flexibility
Permanently altered motion characteristics and biomechanics
Potential for accelerated degeneration of the discs above and below the fused level that can lead to more pain and the need for more surgery

Artificial disc replacement offers a reversible, viable alternative to fusion that possibly avoids the accepted shortcomings of fusion. By inserting an artificial disc instead of performing spinal fusion, there is the possibility of reducing damage to nearby discs and joints. This is because artificial disc replacement allows for motion preservation, near normal distribution of stress along the spine and restoration of pre-degenerative disc height.

How a Disc Is Replaced

Spine surgeons at the Cedars-Sinai Spine Center are at the forefront of development and evaluation of a safe and effective artificial disc. The evolution for hip and knee replacement has taken more than 40 years to reach its current stage of technology in materials, design and technique. Although the idea of an artificial disc is not new, artificial disc replacement technology has just in the recent decade become mature enough to be used clinically in extensive testing in Europe. The unique biomechanical challenges of artificial disc replacement have presented a challenge of both design and material.

Although revolutionary in material and design, the technique to install an artificial disc (whether in the neck or low back) is routine and safe. In both traditional disc surgery and artificial disc replacement the procedure begins by removing the gelatinous disc between the vertebrae.

Once the disc is removed, two metal plates are pressed into the bony endplates above and below the space now vacated by the disc. Metal spikes hold these plates in place on the bone. Eventually bone will grow over and around the metal plates. A plastic spacer made of a polyethylene core is put between the plates. The patient's own body weight compresses the spacer after the surgery is complete. The device allows for six degrees of freedom.

Recovery from artificial disc replacement and care afterwards are much like that for other anterior approaches to lumbar spine surgery. In some cases, recovery is faster than for a traditional fusion surgery. There is less pain from the procedure and fewer complications in general. The materials used in artificial disc replacements are similar the materials used in routine hip and knee replacement surgery. The materials are designed not to cause sensitivities once in the body

'Hitchhiking' anti-cancer viruses ride blood cells

By James GallagherHealth and science reporter, BBC News

A tumour-killing virus can sneak around the body by "hitchhiking" on the back of blood cells, researchers have shown.

It is hoped reoviruses can be used to treat cancer, but there were fears they would not work if the immune system could wipe them out.

A study published in Science Translational Medicine showed the viruses could hide in the blood and reach their target.

Experts said it was an important step in advancing cancer therapies.

Reoviruses are normally harmless, but they can cause stomach upsets and colds in childhood. However, it seems they have the ability to infect and kill some cancerous cells while leaving the surrounding tissue unharmed.

However, experiments on mice suggested the virus would not survive in the blood as the immune system would destroy it.

It meant the virus would need to be injected directly into the tumour or be given with drugs to suppress the immune system.

Stealth mode

A study in 10 people at the University of Leeds and The Institute of Cancer Research, at the Royal Marsden Hospital, showed that the virus could escape the immune system by hiding in the blood.

“Start Quote

Viral treatments like reovirus are showing real promise in patient trials”

Dr Kevin HarringtonThe Institute of Cancer Research

All the patients had advanced bowel cancer which had spread to the liver, and were injected with doses of the reovirus ahead of their scheduled surgery.

The virus was detected in the tumour, but not the liver, meaning it was selectively targeting the cancer. In the blood, the virus was detected in blood cells, not the liquid blood plasma all the cells float in, meaning it was "hitchhiking", the researchers said.

Prof Alan Melcher, from the University of Leeds, said the virus was "even cleverer" than previously thought.

"By piggybacking on blood cells, the virus is managing to hide from the body's natural immune response and reach its target intact."

He told the BBC he had "no doubt" the virus would be eventually used "in combination with chemotherapy".

'Important next step'

Dr Kevin Harrington, from the Institute of Cancer Research, said: "Viral treatments like reovirus are showing real promise in patient trials.

"This study gives us the very good news that it should be possible to deliver these treatments with a simple injection into the bloodstream."

Why reoviruses affect only cancer cells is not entirely understood. Cancer cells behave very differently to healthy cells, which may make them more susceptible to infection.

Doctors are already testing the virus in some trials in people, such asstudies on head and neck cancer .

Prof John Bell, from the University of Ottawa, has researched using genetically modified viruses to attack cancer cells.

He said viruses could be "exquisitely selective" in targeting tumours, and that this latest study had shown how safe the technique was.

"This study is an important next step in advancing oncolytic virus therapies into cancer patients."